// 实现这个项目的构建任务
const { src, dest, watch, series, parallel } = require('gulp')
const plugins = require('gulp-load-plugins')()
const scss = require('gulp-sass')(require('node-sass'))
const bs = require('browser-sync').create()

const style = ()=>{
    return src('src/assets/styles/*.scss', { base: 'src' })
            .pipe(scss({ outputStyle: 'expanded'}))
            .pipe(dest('temp'))
            .pipe(bs.reload({ stream: true }))
}

const script = ()=>{
    return src('src/assets/scripts/*.js', { base: 'src' })
            .pipe(plugins.babel({
                presets : ['@babel/preset-env']
            }))
            .pipe(dest('temp'))
            .pipe(bs.reload({ stream: true }))
}

const page = ()=>{
    return src('src/*.html', { base: 'src' })
            .pipe(plugins.swig({data: {}, defaults: { cache: false }}))
            .pipe(dest('temp'))
            .pipe(bs.reload({ stream: true }))
}

const image = ()=>{
    return src('src/assets/images/**', { base: 'src' })
            .pipe(plugins.imagemin())
            .pipe(dest('dist'))
}
const font = ()=>{
    return src('src/assets/fonts/**', { base: 'src' })
            .pipe(plugins.imagemin())
            .pipe(dest('dist'))
}
const extra = ()=>{
    return src('public/**', { base: 'src' })
            .pipe(plugins.imagemin())
            .pipe(dest('dist'))
}
const clean = ()=>{
    return src('dist/*')
            .pipe(plugins.clean())
}
const useref = ()=>{
    return src('temp/*.html', { base: 'temp' })
            .pipe(plugins.useref({ searchPath: ['temp', '.'] }))
            .pipe(plugins.if(/\.js$/, plugins.uglify()))
            .pipe(plugins.if(/\.css$/, plugins.cleanCss()))
            .pipe(plugins.if(/\.html$/, plugins.htmlmin({ collapseWhitespace: true, minifyJS: true, minifyCSS: true })))
            .pipe(dest('dist'))
}
const serve = ()=>{
    watch('src/assets/styles/*.scss',style)
    watch('src/assets/scripts/*.js',script)
    watch('src/*.html',page)
    watch([
        'src/assets/images/**',
        'src/assets/fonts/**',
        'public/**'

    ],bs.reload)
    bs.init({
        notify: false,
        port: 2021,
        server:{
            baseDir: ['temp', 'src', 'public'],
            routes: {
                "/node_modules": "node_modules"
            }
        }
    })
}

const compile = parallel(style, script, series(page, useref), image, font, extra)
const build = series(clean, compile, serve)
module.exports = {
    useref,
    compile,
    clean,
    build
}